I am stuck on the following problems. I don't know how to 'plug in,' or substitute, the correct way--please show me how.
1) The yield V is in millions of cubic feet and x is the number of years. What is the time needed to yield 2.1 million cubic feet?
2) With buying power B and t years, when will B(t) be half of what it is today?
For this one my teacher said that since the original buying power was 1 I had to change it to .5. She said I should put the .5 in front of the (0.92) but I still don't know what to do from there.
Also for this one logarithm, I think I've done it right, can you verify?
1) logx^2 = -10
x^2 = 10^-10
x = 100000